The periodic table of science fiction. A hundred or so short-shorts, one per element, by one of my favorite authors. I don't think I've read anywhere near all of them, but every once in a while I like to browse a few randomly.

And the wooden periodic table, awarded the 2002 Ig Nobel prize. This one takes itself a little more seriously as a periodic table, but it still has lots of interesting photos and short anecdotal text about each element. And it really is a wooden table.